Even with a perfect guide, things can go wrong. Here are solutions to some common problems:
The game shows a blank save or resets to 0%.
C:\Users\[YourUsername]\Documents\My Games\Binding of Isaac Repentance Step 2: Backup Your Current Progress
Q: Will using a 100% save file affect my game achievements? A: Yes, using a 100% save file may affect your game achievements and leaderboards.